Underwater liquid storage system



Dec. 10, 1963 w. B. CRAWFORD ETAL 3,113,699

UNDERWATER LIQUID STORAGE SYSTEM Filed May a. 1961 7 Sheets-Sheet 1 Dec. 10, 1963 .w. B. CRAWFORD ETAL ,1 3 699 UNDERWATER LIQUID STORAGE SYSTEM Filed May 5, 1961 7 Sheets-Sheet 2 Dec. 10, 1963 w. B. CRAWFORD ETAL UNDERWATER LIQUID STORAGE SYSTEM 7 Sheets-Sheet 3 Filed may 5. 1961 DON Dec. 10, 1963 W. B. CRAWFORD ETAL UNDERWATER LIQUID STORAGE SYSTEM Filed May 3, 1961 '7 Sheets-Sheet 4 2I6 21s l Q31? 2m 219 219 Q w. B. CRAWFORD ETAL 3,113,699

UNDERWATER LIQUID STORAGE SYSTEM Dec. 10, 1963 7 Sheets-Sheet 5 Filed May 6, 1961 m: 8 m9 1 llllll 1 1% m5 1 5.; 2 I I 1963 w. B. CRAWFORD ETAL 3,1 3,69

UNDERWATER LIQUID STORAGE SYSTEM 7 Sheets-Sheet 6 Filed May 3. 1961 Dec. 10, 1963 w. B. CRAWFORD ETAL 3,113,699

UNDERWATER LIQUID STORAGE SYSTEM 7 Sheets-Sheet 7 Filed May 6. 1961 United States Patent ()flice 3,113,698 Patented Dec. 10, 1963 3,li3,$9 UNDERWATER LTQUTD TGRAGE SYSTEM William B. Crawford, Mishawalra, End, and Walter C.

Timmerman, Sn, Walter C. Timmerman, I ia, (Ilimies l3.

Pekor, and Fares K. Hanna, Houston, Tex, assignors to United States Rubber Qompany, New York, N.Y.,

a corporation of New Jersey Filed May 3, 1961, tier. No. 107,499 12 Claims. (til. 222- 23) This invention relates to an underwater liquid storage system and, more particularly, to such a storage system utilizing rubbe -like collapsible containers.

Underwater storage systems have been disclosed in a number of United States patents. (See, for example, US. Patent Nos. 2,383,840 and 2,487,786.) The storage systems disclosed therein, however, have all contemplated the utilization of smaller flexible storage tanks. Where a storage system is to hold quantities of liquids in the range of 1200 barrels to 25,000 barrels, additional problems arise which have not been encountered previously. It is the object of the present invention, therefore, to provide a solution to these problems for a system of this size.

Since the flexible, collapsible container itself must not only function as an underwater storage tank, but must also serve as an expellant bag (see especially US. Patent No. 2,3 83,840), it must be designed so that the collapsing and expanding that occur during repeated filling and emptying cycles will not cause damage during the course of long periods of service. In addition, the flexible container must withstand the environ-mental conditions associated with extended underwater storage and must not be adversely affected by sea Water and marine growth.

Additionally, the underwater storage of large quantities of liquids raises problems in anchoring the apparatus to the bottom of the body of water in which it is submerged and also problems concerning restraining and holding the containers themselves in proper position relative to the anchoring system. Where the liquid to be stored has a specific gravity less than that of water, for example, fuel oil, the assembly must be capable of withstanding large buoyant forces. It must also be able to withstand the horizontal drag forces produced by strong underwater currents and must be able to support the weight of the flexible container and attached equipment when the same is empty. If the collapsible container itself is to vary in profile from a fiat envelope in the empty state to an approximately oval, elliptical or cylindrical shape in the filled state, the restraining system must not impair the ability of the container to thus change its shape.

The anchoring system must be designed with an adequate safety factor, so that failure of one component will not result in a storage container breaking loose. The safety factor must also be sufiicient to compensate for corrosion and the consequent gradual deterioration which results therefrom. The anchoring system also must be suitable for use in both hard and soft bottom conditions.

A filling and emptying hose is, of course, an indispensable part of any underwater liquid storage system. Such a hose would normally abrade and/or apply other destructive forces to a rubber-like container. Thus, some form of header tank has been found necessary to absorb these forces and leave the flexible container undisturbed. The header tank would normally be anchored to the sea floor adjacent to one end of the flexible container. Where, however, the underwater storage system comprises a number of collapsible containers, a long header tank is advisable to serve as a manifold for the multiple installation, so that one set of filling and emptying hoses can serve all the flexible containers.

The large volume storage system herein contemplated requires a means of accurately measuring the quantity of containers.

liquid stored in the containers at any time. Thus, it is necessary to have a metering system to indicate the amount delivered to or withdrawn from the containers. Furthermore, since it must be assumed that no single agency or vessel will use the storage system, it is essential that this metering system comprise self-contained instrumentation equipment.

Since the basic container unit itself is, of course, constructed of flexible material, a positive means to prevent over-filling the same is also an absolute necessity. Thus, the underwater storage system herein contemplated requires a completely reliable automatic shutoff valve positioned at each individual container. The valve must be capable of preventing over-filling, which could cause total destruction and loss of contents.

In some installations it may be desirable to protect the flexible containers from contact with the filling and emptying hoses and the various anchor lines required. If so, an intermediate underwater floating swivel-type buoy can be used. The buoy would provide intermediate support for the hose and, as such, would have to be adapted to withstand those forces that would otherwise be transmitted directly to the underwater containers.

Hence, it is an object of the present invention to design an underwater storage system utilizing lightweight flexible storage containers that can function as a repository for amounts of liquids ranging from a few barrels to 25,000 barrels or more in each assembly.

It is a further object of the present invention to provide such an underwater cache that will be suitable for the storage of a variety of liquids, especially fuel oils.

It is a [further object of the present invention to design a storage system that will solve all of the above-enumerated problems peculiar to large installations.

In accordance with these objects, we have designed an underwater liquid storage system comprising one or more essentially fluid-impermeable, flexible collapsible storage Based on the principle of water displacement, the containers will change shape whenever liquids are induced or withdrawn and thus no difl'erential pressure will occur across the container wall notwithstanding the buoyant force of the contained liquid. The containers themselves are horizontally oriented and are disposed within a substantially rectangular, rigid frame adapted to rest on the bottom of the body of water in which they are submerged. Means are provided to anchor the collapsible oontm'ners and enclosing frame to the bottom and to restrain them from movement due to buoyant forces and wave and current forces.

The system further comprises a plurality of straps extending in two mutually perpendicular directions and attached to the rigid frame, said straps forming a network to enclose the collapsible containers top and bottom and to restrain them from vertical movement when filled and from rubbing on the bottom when empty. The straps thus form a restraining harness and, being flexible, will not prevent the containers from changing shape when liquids are withdrawn or added. The system further comprises a header tank communicating with the individual containers. A filling and emptying hose attached at one end to the header tank and having a valve at its other end is also provided.

An underwater buoy disposed directly above the container system and adapted to provide intermediate support for the filling and emptying hose may be a part of the system. Means are provided to indicate the volume of liquid stored in the system at all times and means are also provided to prevent over-filling of the individual containers. Finally, the system comprises means to raise the end of the filling and emptying hose adjacent the surface of the water.

The invention having been broadly described, a more detailed description is given hereafter with reference to the accompanying drawings, wherein:

FlG. l is a perspective view of a 1200 barrel (50,000 gallon) underwater liquid storage system, having a singie flexible, collapsible container, which will be used to illustrate the invention;

FIG. 2 is an end view, partly in section, of the container, rigid frame, anchoring means and header tank of the system shown in FIG. 1;

FIG. 3 is a perspective view of a multi-container underwater storage system constructed in accordance with our invention and capable of storing amounts up to 25,000 barrels;

FiG. 4 is a sectional view taken on line 44 of FIG. 1 and showing the automatic shut-oif valve in elevation;

FIG. 5 is a vertical sectional view taken through the centerline of the automatic shut-off valve of FIG. 4;

FIG. 6 is a sectional view taken on line 66 of FIG. 1 and showing the construction of one of the components of the metering system;

FIG. 7 is a sectional view taken on line '7--7 of FIG.

FIG. 8 is a sectional view taken on line 8-8 of FIG. 6;

FIG. 9 is a schematic view of the metering system;

FIG. 10 is a sectional view taken on line 1010 of FIG. 1, showing the details of construction of the underwater buoy;

FIG. 11 is a sectional view taken on line 11-11 of FIG. 10; and

FIG. 12 is a sectional view taken on line 12-12 of FIG. 10.

The Overall System FIG. 1 illustrates a 1200 barrel (50,000 gallon) underwater liquid storage system, particularly designed for off-shore storage of fuel oil. In general, the system comprises a flexible, collapsible container 20 enclosed within a substantially rectangular, rigid frame 30, which is adapted to rest on the bottom of the body of water in which the system is submerged.

The frame 30 is anchored to the bottom and restrained from lateral movement by means of four piles 40. A network of straps 50 forming a tank-restraining harness encases the container 20 top and bottom and suspends it within the rigid frame 30.

Filling and emptying of the container 20 is accomplished by means of a flexible hose 60, which extends from the surface of the body of water to a header tank 70, which is an integral part of the rigid frame 30. The header tank 70 itself communicates directly with the container 20 by means of a flexible hose 61.

The system is equipped with a metering system adapted to indicate the volume of fuel contained at all times. The metering system comprises a pressure actuated signaling device 100, pressure lines 110 and 111, and a manometer type of visual gauge 150 which is supported at the surface.

To prevent the possibility of over-filling the container, it is equipped with an automatic shut-off valve 200, which operates mechanicaliy when the container 20 is expanded to the depth that provides the specified capacity.

To protect the container 20 from contact with the filling and emptying hose 60 and the various anchor lines required, an intermediate underwater floating swivel-type buoy 250 is provided, as shown in FIG. 1. Buoy 250 is maintained in position by four steel cables 251, as shown.

Finally, hose 60 is supported at the surface of the water by a floating buoy 300, having suitable liquid transfer control valves. Buoy 300 is maintained in position by a steel cable 301 connecting it with underwater buoy 250. Buoy 300 may desirably be provided with a navigation light 302; the buoy also furnishes support for manometer 150.

Each of these components will now be described in complete detail, thus to constitute a full disclosure of the invention.

The Flexible Container The container 20 is formed in the shape of a rectangular flat envelope. When filled to rated capacity, it is approximately elliptical in cross-section. To have a 50,- 000 gallon capacity, it should be approximately 22 feet wide by 70 feet long when empty; when filled to rated capacity it will then be approximately 20 feet wide, 68 feet long and 6 feet high. The general configuration of the filled container is best described by the adjectives pillow-shaped or oval-shaped, although it should be understood that modifications in the basic shape are possi ble.

Due to its shape, container 20 will not fold or crease during the transition from the full to the empty condition. The minimum of flexing which occurs thus insures a long service life.

Container 20 is constructed of two plies of nylon fabric coated with appropriate synthetic rubber compounds. The nylon fabric used in the inner ply is a 4 ounce square woven material. This inner ply, which is exposed to the liquid contents, is coated on both sides with a fuel resistant Buna N compound.

The outer ply is used primarily for reinforcement. A 13 ounce square woven nylon fabric has been found suitable. This ply is coated on the hidden side with a Buna N compound and on the outer surface, which is exposed to the elements, with neoprene, which has been used as an exterior coating on marine hose for many years. The coating compounds used are basically the same as those used to coat flexible fabric ground storage containers in use for many years.

Containers constructed as above described have withstood satisfactorily the environmental conditions associated with extended periods of underwater storage. Although they become covered with marine growth, the material does not deteriorate. Furthermore, the abovedescribed construction is resistant to diffusion by sea water, that is, the construction does not permit any permeation or diffusion of either water or fuel oil through the container wall. Thus, the construction is essentially fluid impermeable.

The 50,000 gallon container weighs approximately 1800 pounds. The total thickness of the container wall is 0.09 inch, thus the weight of the construction is in the order of 0.50 pound per square foot.

Tank-Restraining Harness As shown in FIGS. 1 and 2, container 20 is encased in a network of straps 50, which forms a tank-restraining harness. The straps 50 suspend the container within the rigid frame 30.

The network of straps 5-0 provides adequate support to container 20 to resist bouyant loads when filled with fuel oil and also supports the weight of the container assembly when empty. The straps themselves are fabri cated of synthetic fiber webbing, preferably of high strength nylon or Dacron brand polyester fiber, which resists deterioration from exposure to salt water and marine organisms. The individual straps should have tensile strengths in the range of 20,000 to 30,000 pounds. Webbing 3 /2 inches wide has been found to be satisfactory.

Loop splices are required in the ends of the individual straps to transfer the load to frame 30. The splices are made by sewing them with maximum stitch efliciency. A rubber spool is used in the loop and the attachment to frame 30 is made by means of a pin through the hole in the spool. Attachment of the straps to the frame is illustrated in FIGS. 1, 2 and 4.

Anchoring System Container 20 is attached by means of the above-described tank-restraining harness to a substantially rectangular, rigid frame 30, which is adapted to rest on the bottom of the body of water in which the entire system is submerged. Frame 39 is itself anchored to the bottom and restrained from lateral movement by means of four piles ll The frame 39 and the piles l-ll comprise the anchoring system.

An underwater storage system designed to hold 50,000 gallons of 0.83 specific gravit fuel oil will generate a buoyant force of 1.26 pounds/ gallon or a total vertical force of approximately 63,680 pounds. additionally, a 5 knot current acting on the full length of a container of the size of container 20 will generate a drag load of approximately 25,300 pounds. Thus, the anchoring systern must be adequate to withstand both forms of loading plus forces generated by wave action.

The combination of frame 3% and piles 40 is satisfactory to stabilize the container and prevent lateral movement under the worst combination of loading. It would be completely unreasonable to attempt to anchor the container with ballast alone, as the very substantial lateral or drag forces that are encountered (as mentioned above) would cause the entire assembly to move in a horizontal direction even though the amount of ballast be far greater than the buoyancy produced by the 50,600 gallons of fuel oil. Thus, the combination of the rigid structural frame and the four piles provides the necessary resistance in the most economical manner.

Frame 33*, when attached to piles 4f supplies the necessary ballast and bending strength to maintain the container 2'9 in the desired attitude. Piles ll? are sufficient to Withstand the worst lateral forces that are encountered.

As can be seen from FEGS. l and 2, frame 39 is built in a substantially rectangular shape. Upper chord members 3i are joined to lower chord members 32 by a tubular steel truss 33. Container 29 is suspended from up per chord members 31 by means of the network of straps 5b. Upper and lower chord members 31 and 32 are also formed of tubular steel pieces.

Piles it? are made of steel and are driven through four guides 43 on frame 3% to a penetration of approximately 80 feet. Piles are preferably made 26 inches in diameter. Since tne lower chord members 32 will normally be buri d to some extent in the mud of the bottom, guides actually penetrate mud for a distance of several feet (see PEG. 2) and act to stabilize the entire assembly when it is lowered in position and before the piles are driven.

Lower chord members 32 are provided with l-bcam shaped cross members 34 for rigidity and strength. Addit nal lateral braces 35 are provided as required.

Pile-to-iacket connections (not shown) lock piles 4-1) to guides 41 and maintain stability of frame 3%? and container 28 in the desired position.

In practice, the complete assembly of container 2 frame 3 3 and piles as is normally assembled on shore and towed or otherwise transported to the location site. Tubular frame 3% is then flooded with water, thus to car-"e the entire assembly to sink. This procedure fully uti zes the weight of frame as ballast. The total weight of frame and piles ill is approximately 82,000 pounds, whi h may be compared to the above-calculated buoyant force of 63,003 pounds, and is sufficient to will"- stand the buoyant force. The piles h) are designed to counteract lateral forces created by underwater currents nd waves and also supply additional holding forces to withstand the buoyant force.

Header Tank in F163. 1 and 2, one of the steel tubes forming the upper ch d member 31 of frame as is utilized as a header tank 73 Header tank 7% protects flexible container from damage, as above described.

Header tank 79 is preferably constructed of 12% inches by 0.312 inch thick steel tubing. This weighs ap- As shown 6 proximately 41.5 pounds per linear foot in air and, therefore, has a buoyant force of 15 pounds er linear foot when submerged in water. The tubing has a gross weight of pounds per linear foot in air when filled with 0.88 specific gravity fuel oil and thus weighs 29 pounds per linear foot when submerged.

Header tank 'Yil has two flange connections 71 and 7'. Connection 731 joins the tank to flexible hose til, which communicates directly with container 2%; connection '72 joins the tank to the main hose es via another length of flexible house 62. (See FIG. 1.) Thus, header tank 79 absorbs the forces from fuel hose 6% and leaves container 2i undisturbed.

Connection '71 consists of a standard 6 inch diameter pipe saddle 73 and a standard slip-on flange fitting 74, adapted to be connected to a flange fitting as on the end of hose er. (See PEG. 4.) Hoses all and 62 are preferably made of 6 inch diameter fuel-resistant line.

Automatic Shut-0fi Valve FIGS. 1, 4 and 5 show the automatic shut-off valve Zt'ltl, which is attached directly to container Ztl to prevent over-filling, as above described.

Valve Ziltl connects hose 61 to container 2%, as shown in FIG. 4. Hose 61 terminates in a standard flange fitting 64, which is adapted to be connected to a flange fitting 201, welded or otherwise attached to the side of valve 2%.

Valve Zlltl is positioned on the upper side of container 29 in such a manner as to be at the high point of the container when filled. As shown in FIG. 5, it is attached to a manhole cover plate 2% by bolts 2% and nuts 264. A gasket 2435 insures a tight seal between manhole cover plate 2-32 and the lower housing of the valve. Lower housing 2126 is itself built up of suitably sized annular plates 2%? and 2th; and a cylindrical section 209, which are joined together by welding or other suitable means. Manhole cover plate 2532 is, in turn, attached to a fitting molded as an integral part of container 20.

Valve Zd-ll has a bell-shaped body portion 219, to which flange fitting Zlll is attached. Fuel oil is pumped into the body portion Zltl by means of hose 61, as above described, and thence into container 29.

The lower part of valve 260 is comprised of a body portion 211. Disposed within valve body portion 211 is a guide mount 212, threadedly engaged as shown in FIG. 5. Disposed in guide mount 212 is a shock chamber ring 213, which is threadedly engaged into an annular seat 214 in guide mount 212. A shaft 215, having a reduced diameter upper portion 218, also fits within guide mount 212, as shown.

A guide sleeve 21d fits around shaft 215 and is provided with two drilled holes 217 to accommodate two steel balls 219.

A spring retainer plate 22% is attached to the upper end 221 of shaft 215 by means of two nuts 222 and two washers 223, threadedly engaged with shaft 215.

Mounted exteriorly of guide sleeve 2% is a plunger 224. Plunger 224 is recessed as at 225 to accommodate steel balls 219. The lower surface of plunger 224 is adapted to contact the upper part of valve body 211, which is formed into a valve seat 211a.

Threadedly engaged with plunger 224 is a spring retaining sleeve 226. Threadedly engaged to the end 227 of guide sleeve 216 is a valve stop 223.

A valve return spring 229 is disposed around shock chamber ring 213 and is seated in an annular slot 230 in plunger 224. A shaft return spring 231 is disposed around retaining sleeve 226, the upper end being seated in spring retainer plate 220, the lower end resting against the upper surface of plunger 22 i.

Threadedly engaged to the bottom end 232 of shaft 215 is a lanyard fitting 233, which is attached by means of a lanyard cord 234 to a fitting 235 attached to the opposite side of container 20. (See FIG. 4.) ;Lanyard 7 fitting 233 is retained in position on end 232 of shaft 215 by a lock nut 233a.

An O-ring 236 is used to insure a tight connection be tween valve body 211 and bell-shaped body portion 210. In turn, valve body 211 is sealed to plate 208 of lower housing 2% by a body sealing gasket 237. Connection is made between valve body 211 and plate 2118 by means of bolts 238.

In operation, fuel oil is pumped through hose 61 and flange fitting 2&1 into body portion 21b of valve 2%. During the initial filling operation, plunger 224- is locked in an upward position by the two balls 219, which fit into recess 22%. Plunger 224 remains locked in this position until sufficient fuel oil is pumped into container to cause lanyard cord 234 to pull shaft 215 downwardly enough to release balls 219. When balls 219 are free to move inwardly adjacent the upper portion 213 of shaft 215, plunger 224 is released.

Release of plunger 224 allows shaft return spring 231, which was compressed when shaft 215 was pulled down wardly, to force plunger 224 down. Fuel oil flowing through flange fitting 2511 also exerts pressure on the upper surface of plunger 224. This pressure, in combination wtih the pressure exerted by shaft return spring 231, causes plunger 2% to descend and fit tightly against valve seat 211a. This action closes off the interior of container 2%, thereby preventing over-filling.

To preevnt plunger 224 from ramming sharply against valve seat 211a, thereby to cause damage to both, the lower portion of plunger 224 is adapted to fit within shock chamber ring 213. Shock chamber ring 213 can be equipped with small vent holes at its base (not shown) or a bleeder hole 249 can be drilled, as shown, in guide mount 212. This will permit fuel oil trapped between plunger 224 and shock chamber ring 213 to be forced out slowly, thus providing the necessary damping action.

Plunger 224 remains seated against valve body 211 until the fuel pumping is terminated or until a valve between fiange fitting 2111 and the fuel pump is closed. As soon as the fuel flow is cut-off by either of the abovementioned methods, valve return spring 22!! causes plunger 224 to move upwardly, thereby opening valve 260. The valve will remain in this position until such time as additional fuel is pumped into container 21).

An additional safety feature has been incorporated into valve 200 to prevent over-filling in case the abovedescribed mechanism fails for any reason. If plunger 224 does not descend against valve seat 211a of valve body 211 due to failure of shaft return spring 231, sticking of balls 219 or any other reason, additional force applied to lanyard fitting 233 will compress spring 231 suificiently to permit spring retainer plate 220 to contact sleeve 226. Since sleeve 226 is positively attached to plunger 224, it will force the latter down until the plunger ultimately comes in contact with valve seat 211a, thereby shutting off the fuel flow. This provides a safeguard which can only be rendered inoperative by a total mechanical failure of valve 261).

In the event that valve 2% is shut off by this abovedescribed pulling down of plunger 224, the fuel system pumps will have to be reversed to create a suction pressure above plunger 224 to lift the same. Such suction, when sufficient to overcome the force exerted by lanyard cord 234, will cause plunger 224 to move upwardly thereby disengaging it from valve seat 211a.

When emptying container 20, the operation is virtually the opposite of that above-described. Plunger 224 is maintained in an upward position by valve return spring 229, thereby permitting fuel oil to flow readily between valve body 211 and plunger 224- and ultimately through flange fitting 201 and out through hose 61.

Thus, automatic shut-off valve 2% is seen to be a positive means of preventing over-filling of container 20. It is completely reliable and is required by a system of this type.

Zlfetcring S yslcm FIGS. 1 and 6-9 show the metering system, which is adapted to indicate the volume of fuel contained at all times. Broadly, the metering system comprises a pressure actuated signaling device Hill, which is connected to a manometer type of visual gauge 159 by pressure lines and 111.

Signaling device 1% is positioned on the upper side of container 29 in such a manner as to be at the high point of the container when filled. As shown in FIG. 6, it is attached to a manhole cover plate 101 by bolts 162. A gasket 103 insures a tight seal between manhole cover plate 101 and the lower housing 104 of the device. Manhole cover plate 191 is attached to an integrally molded fitting in container 20.

The device 1% is essentially comprised of a lower chamber and an upper chamber 1%. Lower chamber 1-35 is separated from the interior of container 20 by a perforated guard plate 11W. Plate 197 serves merely to protect the mechanism 11?? extending into lower chamber 1&5.

The body portion 1% of device 1130 is essentially as shown in FIG. 6. Drilled holes 1111a and 111a serve to accommodate pressure lines 119 and 111, respectively, as above described. Body portion 105 includes a central plate 112, which serves to divide the device into the two chambers 11% and 1%, above mentioned.

A hearing 113 fits into a hole 114 in plate 112. Bearing 113 is maintained in position in hole 114 by a re tainer nut 115, threadedly engaged as shown. A gasket 116 insures a tight seal.

A push rod 117 fits within bearing 113, as shown. Push rod 117 is threaded at each end. The ends are of reduced diameter. A stop ring 118 fits on the lower end 119 of push rod 117 and is seated against shoulder 121), which is formed by the reduction in diameter. Ring 118 is maintained in position by a lock not 121 and a hex head not 122.

Upper chamber 1% is defined by a rubber diaphragm 12?, which is clamped to body portion 109 by a retainer ring 124. Retainer ring 124 is bolted to body portion 169 by a plurality of bolts 125, only two of which are illustrated in FIG. 6.

The upper end 126 of push rod 117 is connected to rubber diaphragm 123 by two dish-shaped retainer plates 127 and 128, as shown. Again, since the upper end 126 of push rod 117 is of reduced diameter, a shoulder 129 is formed, against which retainer plate 128 can rest. Retainer plates 127 and 128 are maintained in position by a lock nut 131i and a hex head nut 131.

Lower chamber and upper chamber 1% communicate with each other by means of a slot 132 machined in the surface of push rod 117. This is as shown in F168. 6, 7 and 8. When a portion of slot 132 extends below the lower surface 113a of bearing 113, fuel oil in lower chamber 1155 can flow upwardly along slot 132 and thence into upper chamber 1%.

The upper surface 1131) of bearing 113 is grooved, as shown in FIG. 8. A circular slot 133 communicates with slot 132 in push rod 117, thus to permit the fuel oil which comes from lower chamber 105 to flow out into upper chamber 1%. Circular slot 133 in turn communicates with four radially-extending slots 134 and it is along these that the fuel oil flows.

Push rod 117 is provided with two circumferentially extending grooves 135, as shown in FIGS. 6 and 7. Two 0ring seals 136 fit in grooves 135. When push rod 117 is pulled up sufiiciently far to cause O-ring seals 136 to engage the lower surface 113a of bearing 113, slot 132 is completely closed off from any communication with lower chamber 1115. This prevents any further flow of fuel oil into upper chamber 106.

Rubber diaphragm 123 is protected from the elements by a perforated protective shield 137.

Lower chamber 1115 and upper chamber 1% are connected to manometer 150 by the two pressure lines 11%) and 111, respectively. This is shown diagrammatically in FIG. 9. Pressure line 110 is equipped with a valve if-111) at its upper end (adjacent manometer 159) and pressure line 111 is similarly equipped with a valve V-111 at its end. The left-hand manometer tube 151 is equipped with two valves V45 2 and V153, as shown. Similarly, the right-hand manometer tube 154- is equipped with two valves V455 and V456, as shown. Pressure line 111) terminates in an exit nozzle 157; pressure line 111 terminates in an exit nozzle 158.

Manometer 1% is filled with water and a valve V459 regulates the supply thereof. Manometer 1519 is also provided with a calibrated scale 1611, as shown.

In operation, fuel oil enters the collapsed or partiallyfilled container 253 through hose 61, as above described. As container 21? fills up, fuel passes through perforated plate 107 into lower chamber 195 and begins to fill pres sure line 1111. Fuel also flows into upper chamber 1616 via slot 132 in push rod 117, circular slot 133 in upper surface 1135 of bearing 113, and radially-extending slots 134, as above described. As upper chamber 1M begins to fill up, fuel oil flows into pressure line 111.

At this stage in the operation, valves V-152 and V1S are closed and valves V4111, V111, V-153 and V455 are open. The valves remain in this position until all air has been expelled from pressure lines 1111 and 111 and fuel oil fills both lines at least to a point above valves V4.53 and V156. When this occurs, valves V153 and V155 are closed.

When valve 1 -156 is closed, fuel oil pumped into upper chamber 106 will cause rubber diaphragm 123 to be pushed upwardly against the pressure exerted by the water depth on its upper surface. When diaphragm 123 adopts a horizontal position (see the phantom lines in FIG. 6), the pressure in upper chamber 1% exactly balances the water pressure above. At this point push rod 117 will have moved up sufficiently far in bearing 113 to cause O-ring seals 136 to come into engagement with bearing 113, also as shown in the phantom lines in FIG. 6. This action Will close off slot 132 in push rod 117, thereby preventing any additional fuel oil from entering upper chamber 1%.

The operation up to this point is completely automatic. If valves V152 and if-155 are now opened, the oil pressure can act on the Water levels in manometer 1513. This will permit the difference between the pressure in upper chamber 1% and lower chamber 1% to be read by the height differential of the water columns in manometer tubes 151 and 15 1-.

Thus, manometer 1% is equipped to measure the pressure differential of the fuel oil within each of pressure lines and 111.

An illustrative example will indicate how the metering system gauges the volume of fuel contained in container 21} at any time. Container 26} with a 5 0,000 gallon capacity is six feet deep when filled, as previously described. For purposes of illustration, it will be assumed that the top of the container is 50 feet below the surface of a body of sea Water.

if We assume that the fuel oil contents has a specific gravity of 0.85 and that the specific gravity of sea water is 1.03, the 50-foot head of sea water at thetop of the container will support a column of fuel oil 60.6 feet high. This would amount to a height differential of oil above sea water of 16.6- feet.

Since the container is 6 feet deep, the pressure at the bottom is equal to that exerted by 56 feet of sea water and is equivalent to a 67.9 foot high column of oil. The pressure differential then, that is, the height of an oil column above the sea-Water surface, is 11.9 feet (67.9 feet minus 5 6 feet).

Thus, when valves V4.52 and V155 are opened, manometer 158 will measure a hei-"ht differential or pressure diiferential Within pressure lines 11% and 111 of 1.3 feet of oil (11.9 feet minus 10.6 feet). This pressure differential reduces to an equavalent pressure of 13.3 inches of water. Thus, when container 20 is completely filled, the difference in Water-column heights between tubes 151 and 154 of manometer 159 will be 13.3 inches. It is obvious that by calibrating manometer scale 161) properly, during an initial filling operation, it is possible to determine accurately the amount of fuel oil in gallons Within container 21) by a direct reading [from the calibrated scale.

Thus, the metering system herein described is capable of indicating the qauntity of liquid stored in container '21) at any time. Since the instrumentation equipment is self-contained, any type of vessel can use the storage system Without having to install special equipment.

Submerged Swivel Buoy FIGS. 1 and 1012 show the intermediate underwater floating swivel-type buoy 250, which can be used to protect container 211 from contact With hose 60 and the various anchor lines required. Buoy 2511 is also adapted to prevent fouling of the various lines and cables needed by the overall system. Broadly, buoy 259' comprises a buoyant chamber 252 and a pipeline section 253, which is attached to buoyant chamber 252 within a center cylindrical opening 254 therein.

As shown in FIG. 1, hose 613* and pressures lines 110 and 111 are attached to floating buoy 31111 for ease in filing and emptying the storage system. As varying wind, Wave and tide conditions are encountered, floating buoy 3% will shift in position relative to the underwater storage system, which action would ordinarily tend to foul lines and cables. To negate this possibility, buoy 251i! is provided. The buoy permits all necessary lines to emanate from a single point, acting as an underwater swivel, and thus keeps the submerged lines free.

Buoyant chamber 252 is preferably cylindrical in shape and, as above mentioned, contains a cylindrical opening 254 passing vertically through its center. Chamber 252 is further divided into four sub-chambers by bulkheads 255, thus to lessen the chance of buoyant failure. (See FIG. 11.) Positioned on the outer surface of chamber 252 is a lug 256, to which cable 301 is attached. (See FIG. 10.) Cable 3111 maintains floating buoy 31111- in position, as above mentioned.

Pipeline section 253 is positioned within buoyant chamber 252, as above mentioned, in such a manner that chamber 252 can rotate thereabout. Section 253 furnishes continuity for hose 611' and pressure lines 110' and 111.

As shown in FIG. 10, section 253 is adapted to transmit the fuel oil that passes through hose or and pressure lines 1151 and 111 through separate pipelines therein, which pipelines are located one within the other. The pipelines are respectively designated 60b, 1111b and 1111). Lines as]; furnishes continuity to hose 6%); line 1111b furnishes continuity to pressure line L10; and line 111b furnishes continuity to pressure line 111. Pressure line 1113 connects lower chamber 105 of signaling device to manometer 151 pressure line 111 connects upper chamber 11% of signaling device 111%) to manometer 15%; all as previously described.

As shown in FIGS. 10 :and 11, line 1111) is disposed within line 11%; line 111112 is itself disposed within line tidb. This construction permits buoy 25 .1 to rotate freely about its vertical axis.

Line 5% is provided with a swivel joint 26th, as, for example, a standard 8 inch swivel joint of galvanized metal, which permits rotation about the vertical axis. Line 1111b is provided with a swivel joint 261, as, for example, a standard 3 inch swivel joint of stainless steel, which permits rotation about its vertical axis. Finally, line 11 112 is provided with a swivel joint 262, as, for example, a standard 1 incln swivel joint of stainless steel, which permits it to rotate about its vertical axis. Thus, lines 61112, 11% and 111b can be swiveled aboutthe vertical axis of the entire buoy 250 as a single unit, although none of the three lines can itself swivel independently of the other two.

Line 6011 is provided with flanged fittings 263 adapted to contact bearings 264, which are themselves attached to chamber 252. Bearings 264 may conveniently be made of Teflon brand of plastic bearing material. This construction permits chamber 252 to rotate with respect to section 253, as above described.

It will be noted that, in general, the upper section 255 of section 253 swivels in much the same manner as buoyant chamber 252, as each is attached to floating buoy 300. The lower section 266 of section 253 will, in general, remain stationary relative to container 20, as this section is attached thereto.

Lower section 266 is provided with four radial lugs 270 (see FIGS. and 12), to which are attached the four steel cables 251, above mentioned.

If desired, means for connecting line 601;, should the latter be desired to be constructed in two parts, may be positioned immediately below swivel joint 260. Such means comprise flanged fittings 271, which may be attached together by means of bolts 272 and nuts 273.

Thus, buoy 250 is seen to be well suited to the type of underwater storage system herein disclosed. Buoy 250 not only protects container from contact with hose 60 and the various anchor lines required, but its swivel action also prevents fouling of the various lines and cables.

M uIti-Coni'ainer Storage System FIG. 3 shows a multi-container underwater storage system suitable for quantities of liquids in the range of 25,000 barrels. The system comprises a plurality of collapsible containers 320 anchored to the bottom by piles 340. Piles 340 are interconnected by cables 33%. A network of stnaps 350 forms a tank-restraining harness encasing each container 320 and suspending it within cables 330.

Although the individual containers 320 may be designed to hold 50,000 gallons (as shown in the system disclosed in FIG. '1), containers holding 100,000 gallons may desirably be used. The containers 320 are preferably connected to a header tank 370, so that only one filling and emptying hose 360 is needed.

An underwater buoy 380 is provided to protect the individual containers 320 from contact with hose 36d and the various anchor lines required. Buoy 380* is maintained in position by steel cables 390.

Hose 36% is supported adjacent the surface of the water by a floating buoy 400, as shown.

Having thus described our invention, what we claim and desire to protect by Letters Patent is:

1. An underwater liquid storage system comprising an essentially fluid-impermeable, flexible walled, horizontallyoriented collapsible container; a substantially rectangular, rigid frame enclosing said container and adapted to rest on the bottom of the body of water in which said container is submerged; means to anchor said frame to the bottom; a plurality of straps extending in two mutually perpendicular directions and attached to the upper part of said frame, said straps forming a network to enclose said container; a header tank communicating with said container; a filling and emptying hose attached at one end to said header tank, said hose having a valve at the other end; means to indicate the volume of liquid stored in said container; a second valve attached to said container to prevent over-filling of the same; and means to raise said other end of said hose adjacent the surface of the water.

2. An underwater liquid storage system as in claim 1, in which said volume indicating means comprise a pressure actuated signaling device mounted on the upper wall of said container, pressure sensing means supported at the surface of the water, and a pressure line communicating between said signaling device and said pressure sensing .means.

3. An underwater liquid storage system as in claim 2, in which said pressure sensing means comprises a manometer adapted to read pressure differences.

4. An underwater liquid storage system as in claim 1, in which said raising means comprises a floating buoy.

5. An underwater liquid storage system as in claim 4, in which said volume indicating means comprise a pressure actuated signaling device mounted on the upper wall of said container, a manometer adapted to read pressure differences mounted on said floating buoy, a pressure line communicating between said signaling device and said manometer, and a volume indicating gauge calibrated to said pressure differences.

6. An underwater liquid storage system as in claim 1, in which said second valve comprises an automatic shutcii valve.

7. An underwater liquid storage system as in claim 6, in which said automatic shut-off valve is mounted on the upper wall of said container.

8. An underwater liquid storage system as in claim 7, in which said automatic shut-off valve is mounted at the point of communication between said header tank and said container.

9. An underwater liquid storage system as described in claim 1, further comprising an underwater buoy disposed directly above said system and adapted to provide intermediate support for said filling and emptying hose.

10. An underwater liquid storage system as in claim 9, in which said filling and emptying hose passes through said underwater buoy, thereby dividing said hose into upper and lower parts.

11. An underwater liquid storage system as in claim 10, in which said underwater buoy comprises a buoyant chamher having a central vertical cylindrical opening therein, a pipeline section rotatably supported in the center of said opening, said pipeline section comprising an upper and a lower part, and a swivel joint connecting said upper and lower parts of said pipeline section, the vertical axis of said swivel joint being co-linear with the vertical axes of said pipeline section and said opening; said lower part of said filling and emptying hose being attached to said lower part of said pipeline section, said upper part of said filling and emptying hose being attached to said upper part of said pipeline section, whereby said upper part of said filling and emptying hose can rotate longitudinally with respect to said lower part of said filling and emptying hose and with respect to said buoyant chamber.

12. An underwater liquid storage system comprising an essentially fluid-impermeable, flexible walled, horizontallyorien-ted collapsible container; a substantially rectangular, rigid frame enclosing said container and adapted to rest on the bottom of the body of water in which said container is submerged; means to anchor said frame to the bottom; a plurality of straps extending in two mutually perpendicular directions and attached to the upper part of said frame, said straps forming a network to enclose said container; a header tank communicating with said container; a filling and emptying hose extending from the surface of the body of water to said header tank, said hose having a valve at the surface end; and underwater buoy disposed directly above said system and adapted to provided intermediate support for said filling and emptying hose, thereby dividing said hose into upper and lower parts, said buoy comprising a buoyant chamber having a central vertical cylindrical opening therein, a plurality of varying diameter pipeline sections rotatably supported in the center of said opening, each of said pipeline sections comprising an upper and a lower part, said pipeline sections being disposed one within the other and being rigidly connected each to the other, each pipeline section further comprising a swivel joint connecting its upper and lower parts, the vertical axes of each of said swivel joints being co-linea-r with each other, co-linear with the vertical axis of said pipeline sections and co-linear with the vertical axis of said Opening in said buoyant chamber; means to indicate the volume of liquid stored in said container, said 13 means comprising a pressure actuated signaling device mounted on the upper wall of said container, pressure sensing means supported at the surface of the Water, and a plurality of pressure lines communicating between said signaling device and said pressure sensing means; the lower parts of said filling and emptying hose and said pressure lines being attached to respectively sized ones of said lower parts of said underwater buoy pipeline sec tions, the upper parts of said filling and emptying hose and said pressure lines bein attached to said respective ones of said upper parts of said underwater buoy pipeline sections, whereby said upper parts of said hose and said pressure lines can rotate as a unit longitudinally with respect to said lower par-ts of said hose and said pressure lines and with respect to said buoyant chamber of said underwater buoy; and means to support said surface end of said filling and emptying hose and said volume indicating pressure sensing means adjacent the surface of the water.

References Cited in the file of this patent UNITED STATES PATENTS 1,456,390 Ludwig May 22, 1923 2,731,168 Watts Jan. 17, 1956 2,894,268 Griebe July 14, 1959 

1. AN UNDERWATER LIQUID STORAGE SYSTEM COMPRISING AN ESSENTIALLY FLUID-IMPERMEABLE, FLEXIBLE WALLED, HORIZONTALLYORIENTED COLLAPSIBLE CONTAINER; A SUBSTANTIALLY RECTANGULAR, RIGID FRAME ENCLOSING SAID CONTAINER AND ADAPTED TO REST ON THE BOTTOM OF THE BODY OF WATER IN WHICH SAID CONTAINER IS SUBMERGED; MEANS TO ANCHOR SAID FRAME TO THE BOTTOM; A PLURALITY OF STRAPS EXTENDING IN TWO MUTUALLY PERPENDICULAR DIRECTIONS AND ATTACHED TO THE UPPER PART OF SAID FRAME, SAID STRAPS FORMING A NETWORK TO ENCLOSE SAID CONTAINER; A HEADER TANK COMMUNICATING WITH SAID CONTAINER; A FILLING AND EMPTYING HOSE ATTACHED AT ONE END TO SAID HEADER TANK, SAID HOSE HAVING A VALVE AT THE OTHER END; MEANS TO INDICATE THE VOLUME OF LIQUID STORED IN SAID CONTAINER; A SECOND VALVE ATTACHED TO SAID CONTAINER TO PREVENT OVER-FILLING OF THE SAME; AND MEANS TO RAISE SAID OTHER END OF SAID HOSE ADJACENT THE SURFACE OF THE WATER. 